Hirondellea, Chevreux, 1889

Horton, Tammy & Thurston, Michael, 2009, Hirondellea sindhusagar (Crustacea: Amphipoda: Lysianassoidea), a new deepwater scavenger species from the Indian Ocean, with a key to the genus Hirondellea *, Zootaxa 2096 (1), pp. 433-441 : 440

Key to the species of Hirondellea

1 Inner ramus of uropod 2 constricted ............................................................................................................................ 2

- Inner ramus of uropod 2 not constricted ...................................................................................................................... 7

2 Epimeron 1 with strong anteroventral tooth ................................................................................................... GUYOTI

- Epimeron 1 rounded anteriorly.................................................................................................................................... 3

3 Epimeron 3 sharply subquadrate posteriorly ........................................................................................ TRIOCULATA

- Epimeron 3 rounded posteriorly .................................................................................................................................. 4

4 Gnathopod 1 with strongly concave palm and distal palmar projection...................................................................... 5

- Gnathopod 1 with slightly concave/transverse palm without palmar projection......................................................... 6

5 Dactyl of gnathopod 1 strongly overlapping palm ............................................................................. ANTARCTICA *

- Dactyl of gnathopod 1 scarcely overlapping palm, meeting palmar projection ..................................... ABYSSALIS *

6 Dactyl of gnathopod 1 strongly overlapping palm, dactyl strongly toothed ............................................. FIDENTER

- Dactyl of gnathopod 1 scarcely overlapping palm, dactyl weakly toothed ............................................... GLUTONIS

7 Dactyl of gnathopod 1 multi-toothed................................................................................................................. GIGAS

- Dactyl of gnathopod 1 not multi-toothed .................................................................................................................... 8

8 Gnathopod 1 propodus elongate, strongly tapering ......................................................................................... DUBIA

- Gnathopod 1 propodus short and broad, barely tapering............................................................................................. 9

9 Lateral cephalic lobe rounded, telson cleft>25% .......................................................................... BREVICAUDATA

- Lateral cephalic lobe subacute, telson cleft <20 %............................................................................ SINDHUSAGAR

* distinction between H. abyssalis and H. antarctica is unclear and awaits further specimens from the type localities and a thorough redescription of both entities.